风管中气流平均速度理论推导及模拟验证

Theoretical Deduction and Simulation Verification of Air Flow Average Velocity in Air Duct

目前对于风管内平均风速的测量通常采用的是等截面积法通过多点测量取平均值。多次测量容易带来误差操作起来也复杂。本文通过理论推导得到层流和湍流情况下圆形及矩形风管内平均风速与测点位置之间的关系式,再通过数值模拟验证了理论公式的准确性。利用推导的理论公式可以实现一次测量得到风管内平均风速,为工程实践过程带来极大的便利。

At present, the average wind velocity measurement in the duct is usually measured by the equal-area rings method, averaging the testing values of multi-spots measurements. Repeated measurements are likely to cause errors and the operations are complex. In this paper, the relationship between the average wind velocity and the position of the measured point in a circular and rectangular duct under laminar and turbulent conditions is deduced theoretically, then the accuracy of the theoretical formula is verified by numerical simulation. By using the deduced theoretical formula, the average wind velocity in the duct can be achieved once, which brings great convenience to the engineering practice process.